Rafael Nadal began his quest for a maiden ATP Finals title by sweeping aside the challenge of Andrey Rublev in his first match of the season-ending tournament on Sunday. Nadal won 6-3, 6-4  to take a 1-0 lead at an empty O2 arena in London.Also Read - WATCH | Rafael Nadal Plays Tennis With 97-Year-Old Man

Nadal, who won a record-extending 13th French Open title in October, has never won the ATP Finals and it’s the only major trophy missing from his brimming cabinet. Also Read - Stefanos Tsitsipas Posts Image of Him in Hospital With Heavily-Bandaged Arm

“It’s important to start well, of course, for the confidence, because winning [in] straight sets helps,” Nadal said after the match. “The serve tonight was very important. I played solidly with my serve. I didn’t suffer much, and that helps [me] to play more relaxed on the return. That’s what I did.” Also Read - Wasn't 100 Per Cent There Mentally: Daniil Medvedev After ATP Finals Loss

“[I’m] happy the way I approached the match. The first match is always difficult, and Andrey played an amazing season. He’s a great guy, too, so I wish him all the very best,” Nadal added.

Rublev admitted to being nervous which affected his serves. “I was not serving good at all because I was a little bit nervous, which is normal,” Rublev said. “When he broke me in the second set I relaxed and I started to serve much better. Then [it] was [a] different game, but it was too late.”

Meanwhile, US Open champion Dominic Thiem got the better of reigning champion Stefanos Tsitsipas in three sets. Thiem, who was beaten to the title last year by Tsitsipas, exacted revenge with a 7-6(5), 4-6, 6-3 in two hours and 17 minutes.

“I experienced in the past four years how important it is to have a good start in this tournament, to ideally win the first match. I am very happy that I did it,” Thiem said after the match.

“Today was a little bit different [than last year]… [There were] only two breaks in the whole match,” said Thiem. “I think the conditions are pretty fast here, so I am super happy with my win. Every win against a Top 10 player at the Nitto ATP Finals is something special and every win against Stefanos is something special, because he is such a great player. He is established and has won so many big titles already.”